杭州市祥符水厂的排泥水处理工程

杭州市祥符水厂采用收集、浓缩、平衡、投加PAM、离心脱水工艺处理排泥水。生产运行实践表明,斜板浓缩池的上清液能达到GB8978—1996的一级排放标准,经离心脱水后泥饼含固率>25%,可实现排泥水的"零排放"。     

谈堤防工程软土地基的处理方法

介绍了软土地基的特性,分析了软土地基上堤防失稳破坏的原因,就堤防工程中常用的软土地基处理方法进行了详细阐述,并提出了软土堤基施工注意事项,以解决好堤防工程的软土地基问题,从而保证堤防工程的整体质量和安全。     

湖北房县变电站边坡稳定性分析

结合工程实例,在掌握工程地质条件的前提下分析了该变电站边坡的失稳机理,并根据Spencer法的基本原理,分析了不同假设条件对边坡稳定性影响,得出了不同状态下边坡的稳定情况。     

碾压混凝土坝层面渗流对坝体渗流场的影响

从碾压混凝土坝的渗透特性出发 ,采用薄层单元模拟层面 ,探讨了碾压混凝土坝层面渗流对坝体渗流场的影响规律 .     

回旋壳体内外曲面三坐标激光非接触测量系统的设计与实现

本文介绍了一种回旋壳体内外曲面三坐标激光非接触测量系统的设计与实现。该系统采用激光和CCD等技术实现了被测体表面快速自动扫描。论述了系统设计思想 ,介绍了该系统的组成。讨论了激光非接触测量头测量原理及系统测量过程 ,最后介始了系统主要技术指标。     

Imidazole Analogs of Vascular-Disrupting Combretastatin A-4 with Pleiotropic Efficacy against Resistant Colorectal Cancer Models

Specific targeting of the tumoral vasculature by vascular-disrupting agents (VDA), of which combretastatin A-4 (CA-4) is a main representative, has been considered a new therapeutic strategy against multidrug-resistant tumors. In addition, CA-4 and analogs are tubulin-targeting agents and can exert direct antitumor effects by different mechanisms. Herein, we analyzed a series of synthetic CA-4 analogs featuring N-methylimidazole-bridged Z-alkenes with different halo- or amino-substituted aryl rings in vitro and in vivo, focusing on models of colorectal cancer. Combined in vitro/in vivo structure–activity relationship studies using cell lines and xenograft tumors susceptible to VDA-induced vascular damage demonstrated a clear association of cytotoxic and vascular-disrupting activity with the ability to inhibit tubulin polymerization, which was determined by specific substitution constellations. The most active compounds were tested in an extended panel of colorectal cancer (CRC) cell lines and showed activity in CA-4-resistant and chemotherapy-resistant cell lines. The bromo derivative brimamin was then compared with the known fosbretabulin (CA-4P) by activity tests on DLD-1- (multidrug-resistant) and HT29- (CA-4-resistant) derived xenograft tumors. Treatment did not induce pronounced vascular-disrupting effects in these tumors. Histological analyses revealed distinct tumor substructures and vessel compositions of DLD-1/HT29 tumors, which clearly differed from the tumor models susceptible to VDA treatment. Even so, brimamin effectively retarded the growth of DLD-1 tumors, overcoming their resistance to standard treatment, and it inhibited the outgrowth of disseminated HT29 tumor cells in an experimental metastasis model. In conclusion, combretastatin analogous N-methylimidazoles proved capable of inducing vascular-disrupting effects, comparable to those of CA-4P. In addition, they showed antitumor activities in models of drug-resistant colorectal cancer, independent of vascular-disrupting effects.     

板壳式换热器在大型合成氨装置上的应用

介绍了板壳式换热器的结构特点及在大型合成氨装置上的应用情况,总结了板壳式换热器在使用中的优点.     

On the Role of Temperature in the Depolymerization of PET by FAST-PETase: An Atomistic Point of View on Possible Active Site Pre-Organization and Substrate-Destabilization Effects

Enzyme FAST-PETase, recently obtained by a machine learning approach, can depolymerize poly(ethylene terephthalate) (PET), a synthetic resin employed in plastics and in clothing fibers. Therefore it represents a promising solution for the recycling of PET-based materials. In this study, a model of PET was adopted to describe the substrate, and all-atoms classical molecular dynamics (MD) simulations on apo- and substrate-bound FAST-PETase were carried out at 30 and 50 °C to provide atomistic details on the binding step of the catalytic cycle. Comparative analysis shed light on the interactions occurring between the FAST-PETase and 4PET at 50 °C, the optimal working conditions of the enzyme. Pre-organization of the enzyme active and binding sites has been highlighted, while MD simulations of FAST-PETase:4PET pointed out the occurrence of solvent-inaccessible conformations of the substrate promoted by the enzyme. Indeed, neither of these conformations was observed during MD simulations of the substrate alone in solution performed at 30, 50 and 150 °C. The analysis led us to propose that, at 50 °C, the FAST-PETase is pre-organized to bind the PET and that the interactions occurring in the binding site can promote a more reactive conformation of PET substrate, thus enhancing the catalytic activity of the enzyme.